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Meyer NR, Morono Y, Dekas AE. Single-cell analysis reveals an active and heterotrophic microbiome in the Guaymas Basin deep subsurface with significant inorganic carbon fixation by heterotrophs. Appl Environ Microbiol 2024; 90:e0044624. [PMID: 38709099 PMCID: PMC11334695 DOI: 10.1128/aem.00446-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 05/07/2024] Open
Abstract
The marine subsurface is a long-term sink of atmospheric carbon dioxide with significant implications for climate on geologic timescales. Subsurface microbial cells can either enhance or reduce carbon sequestration in the subsurface, depending on their metabolic lifestyle. However, the activity of subsurface microbes is rarely measured. Here, we used nanoscale secondary ion mass spectrometry (nanoSIMS) to quantify anabolic activity in 3,203 individual cells from the thermally altered deep subsurface in the Guaymas Basin, Mexico (3-75 m below the seafloor, 0-14°C). We observed that a large majority of cells were active (83%-100%), although the rates of biomass generation were low, suggesting cellular maintenance rather than doubling. Mean single-cell activity decreased with increasing sediment depth and temperature and was most strongly correlated with porewater sulfate concentrations. Intracommunity heterogeneity in microbial activity decreased with increasing sediment depth and age. Using a dual-isotope labeling approach, we determined that all active cells analyzed were heterotrophic, deriving the majority of their cellular carbon from organic sources. However, we also detected inorganic carbon assimilation in these heterotrophic cells, likely via processes such as anaplerosis, and determined that inorganic carbon contributes at least 5% of the total biomass carbon in heterotrophs in this community. Our results demonstrate that the deep marine biosphere at Guaymas Basin is largely active and contributes to subsurface carbon cycling primarily by not only assimilating organic carbon but also fixing inorganic carbon. Heterotrophic assimilation of inorganic carbon may be a small yet significant and widespread underappreciated source of labile carbon in the global subsurface. IMPORTANCE The global subsurface is the largest reservoir of microbial life on the planet yet remains poorly characterized. The activity of life in this realm has implications for long-term elemental cycling, particularly of carbon, as well as how life survives in extreme environments. Here, we recovered cells from the deep subsurface of the Guaymas Basin and investigated the level and distribution of microbial activity, the physicochemical drivers of activity, and the relative significance of organic versus inorganic carbon to subsurface biomass. Using a sensitive single-cell assay, we found that the majority of cells are active, that activity is likely driven by the availability of energy, and that although heterotrophy is the dominant metabolism, both organic and inorganic carbon are used to generate biomass. Using a new approach, we quantified inorganic carbon assimilation by heterotrophs and highlighted the importance of this often-overlooked mode of carbon assimilation in the subsurface and beyond.
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Affiliation(s)
- Nicolette R. Meyer
- Department of Earth System Science, Stanford University, Stanford, California, USA
| | - Yuki Morono
- Kochi Institute for Core Sample Research, Institute for Extra-cutting-edge Science and Technology Avantgarde Research (X-STAR), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Nankoku, Kochi, Japan
| | - Anne E. Dekas
- Department of Earth System Science, Stanford University, Stanford, California, USA
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2
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Hou J, Cai Y, Wang J, Zan S, Li Z, Zhu T. Enhanced bioremediation of cyclohexaneacetic acid in offshore sediments with green synthetic iron oxide and Pseudoalteromonas sp. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:38770-38780. [PMID: 36481851 DOI: 10.1007/s11356-022-24629-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Naphthenic acids (NAs) have been found to exert serious threats on offshore sediment ecosystems and human health in recent years, which entails us the urgent need for NAs remediation. Bioremediation is considered an ideal method for sediment remediation due to ecological sustainability and economic feasibility. However, current bioremediation efficiency of offshore sediments suffers from relatively slow and there has never any attempts to bioremediate offshore sediment NAs contamination hitherto. In this study, the green synthetic iron oxides (gFeOx) based on Laminaria extracts was employed to enhance the biodegradation of NAs (Cyclohexylacetic acid, CHAA) in offshore sediments by Pseudoalteromonas sp. JSTW (an indigenous microorganism). The results showed that CHAA (20 mg·kg-1) in offshore sediments was removed almost 100% within 7 days at 30 mg·kg-1 gFeOx and 0.6 mg·kg-1 Strain JSTW. High-throughput sequencing results revealed that the structure and function of sediment microbial community were essentially restored to uncontaminated levels after bioremediation, highlighting the joint remediation approach is an efficient and eco-friendly method. Overall, this work has firstly provided insights into the application for NAs in situ bioremediation in offshore sediments.
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Affiliation(s)
- Jiaxiang Hou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, P.R.C., 116024, Dalian, People's Republic of China
| | - Yingxue Cai
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, P.R.C., 116024, Dalian, People's Republic of China
| | - Jing Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, P.R.C., 116024, Dalian, People's Republic of China.
| | - Shuaijun Zan
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, P.R.C., 116024, Dalian, People's Republic of China
| | - Zelong Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, P.R.C., 116024, Dalian, People's Republic of China
| | - Tongxian Zhu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, P.R.C., 116024, Dalian, People's Republic of China
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3
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Yadav S, Koenen M, Bale NJ, Reitsma W, Engelmann JC, Stefanova K, Damsté JSS, Villanueva L. Organic matter degradation in the deep, sulfidic waters of the Black Sea: insights into the ecophysiology of novel anaerobic bacteria. MICROBIOME 2024; 12:98. [PMID: 38797849 PMCID: PMC11129491 DOI: 10.1186/s40168-024-01816-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 04/15/2024] [Indexed: 05/29/2024]
Abstract
BACKGROUND Recent studies have reported the identity and functions of key anaerobes involved in the degradation of organic matter (OM) in deep (> 1000 m) sulfidic marine habitats. However, due to the lack of available isolates, detailed investigation of their physiology has been precluded. In this study, we cultivated and characterized the ecophysiology of a wide range of novel anaerobes potentially involved in OM degradation in deep (2000 m depth) sulfidic waters of the Black Sea. RESULTS We have successfully cultivated a diverse group of novel anaerobes belonging to various phyla, including Fusobacteriota (strain S5), Bacillota (strains A1T and A2), Spirochaetota (strains M1T, M2, and S2), Bacteroidota (strains B1T, B2, S6, L6, SYP, and M2P), Cloacimonadota (Cloa-SY6), Planctomycetota (Plnct-SY6), Mycoplasmatota (Izemo-BS), Chloroflexota (Chflx-SY6), and Desulfobacterota (strains S3T and S3-i). These microorganisms were able to grow at an elevated hydrostatic pressure of up to 50 MPa. Moreover, this study revealed that different anaerobes were specialized in degrading specific types of OM. Strains affiliated with the phyla Fusobacteriota, Bacillota, Planctomycetota, and Mycoplasmatota were found to be specialized in the degradation of cellulose, cellobiose, chitin, and DNA, respectively, while strains affiliated with Spirochaetota, Bacteroidota, Cloacimonadota, and Chloroflexota preferred to ferment less complex forms of OM. We also identified members of the phylum Desulfobacterota as terminal oxidizers, potentially involved in the consumption of hydrogen produced during fermentation. These results were supported by the identification of genes in the (meta)genomes of the cultivated microbial taxa which encode proteins of specific metabolic pathways. Additionally, we analyzed the composition of membrane lipids of selected taxa, which could be critical for their survival in the harsh environment of the deep sulfidic waters and could potentially be used as biosignatures for these strains in the sulfidic waters of the Black Sea. CONCLUSIONS This is the first report that demonstrates the cultivation and ecophysiology of such a diverse group of microorganisms from any sulfidic marine habitat. Collectively, this study provides a step forward in our understanding of the microbes thriving in the extreme conditions of the deep sulfidic waters of the Black Sea. Video Abstract.
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Affiliation(s)
- Subhash Yadav
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797AB Den Burg, P.O. Box 59, Texel, The Netherlands
- Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
| | - Michel Koenen
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797AB Den Burg, P.O. Box 59, Texel, The Netherlands
| | - Nicole J Bale
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797AB Den Burg, P.O. Box 59, Texel, The Netherlands
| | - Wietse Reitsma
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797AB Den Burg, P.O. Box 59, Texel, The Netherlands
| | - Julia C Engelmann
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797AB Den Burg, P.O. Box 59, Texel, The Netherlands
| | - Kremena Stefanova
- Institute of Oceanology "Fridtjof Nansen", Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Jaap S Sinninghe Damsté
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797AB Den Burg, P.O. Box 59, Texel, The Netherlands
- Faculty of Geosciences, Department of Earth Sciences, Utrecht University, P.O. Box 80.021, 3508 TA, Utrecht, The Netherlands
| | - Laura Villanueva
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1797AB Den Burg, P.O. Box 59, Texel, The Netherlands.
- Faculty of Geosciences, Department of Earth Sciences, Utrecht University, P.O. Box 80.021, 3508 TA, Utrecht, The Netherlands.
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Qiu Z, Yuan L, Lian CA, Lin B, Chen J, Mu R, Qiao X, Zhang L, Xu Z, Fan L, Zhang Y, Wang S, Li J, Cao H, Li B, Chen B, Song C, Liu Y, Shi L, Tian Y, Ni J, Zhang T, Zhou J, Zhuang WQ, Yu K. BASALT refines binning from metagenomic data and increases resolution of genome-resolved metagenomic analysis. Nat Commun 2024; 15:2179. [PMID: 38467684 PMCID: PMC10928208 DOI: 10.1038/s41467-024-46539-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 03/01/2024] [Indexed: 03/13/2024] Open
Abstract
Metagenomic binning is an essential technique for genome-resolved characterization of uncultured microorganisms in various ecosystems but hampered by the low efficiency of binning tools in adequately recovering metagenome-assembled genomes (MAGs). Here, we introduce BASALT (Binning Across a Series of Assemblies Toolkit) for binning and refinement of short- and long-read sequencing data. BASALT employs multiple binners with multiple thresholds to produce initial bins, then utilizes neural networks to identify core sequences to remove redundant bins and refine non-redundant bins. Using the same assemblies generated from Critical Assessment of Metagenome Interpretation (CAMI) datasets, BASALT produces up to twice as many MAGs as VAMB, DASTool, or metaWRAP. Processing assemblies from a lake sediment dataset, BASALT produces ~30% more MAGs than metaWRAP, including 21 unique class-level prokaryotic lineages. Functional annotations reveal that BASALT can retrieve 47.6% more non-redundant opening-reading frames than metaWRAP. These results highlight the robust handling of metagenomic sequencing data of BASALT.
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Affiliation(s)
- Zhiguang Qiu
- Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China
- AI for Science (AI4S)-Preferred Program, Peking University, Shenzhen, China
| | - Li Yuan
- AI for Science (AI4S)-Preferred Program, Peking University, Shenzhen, China
- School of Electronic and Computer Engineering, Peking University, Shenzhen, China
- Peng Cheng Laboratory, Shenzhen, China
| | - Chun-Ang Lian
- Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China
- AI for Science (AI4S)-Preferred Program, Peking University, Shenzhen, China
| | - Bin Lin
- School of Electronic and Computer Engineering, Peking University, Shenzhen, China
| | - Jie Chen
- AI for Science (AI4S)-Preferred Program, Peking University, Shenzhen, China
- School of Electronic and Computer Engineering, Peking University, Shenzhen, China
- Peng Cheng Laboratory, Shenzhen, China
| | - Rong Mu
- Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Xuejiao Qiao
- Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Liyu Zhang
- Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Zheng Xu
- Southern University of Sciences and Technology Yantian Hospital, Shenzhen, China
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Lu Fan
- Department of Ocean Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, China
| | - Yunzeng Zhang
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Shanquan Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Junyi Li
- School of Computer Science and Technology, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, China
| | - Huiluo Cao
- Department of Microbiology, University of Hong Kong, Hong Kong, China
| | - Bing Li
- Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Baowei Chen
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
| | - Chi Song
- Institute of Herbgenomics, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Wuhan Benagen Technology Co., Ltd, Wuhan, China
| | - Yongxin Liu
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Lili Shi
- AI for Science (AI4S)-Preferred Program, Peking University, Shenzhen, China
- State Key Laboratory of Chemical Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yonghong Tian
- AI for Science (AI4S)-Preferred Program, Peking University, Shenzhen, China
- School of Electronic and Computer Engineering, Peking University, Shenzhen, China
- Peng Cheng Laboratory, Shenzhen, China
| | - Jinren Ni
- Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing, China
| | - Tong Zhang
- Department of Civil Engineering, University of Hong Kong, Hong Kong, China
| | - Jizhong Zhou
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Wei-Qin Zhuang
- Department of Civil and Environmental Engineering, Faculty of Engineering, University of Auckland, Auckland, New Zealand
| | - Ke Yu
- Eco-environment and Resource Efficiency Research Laboratory, School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen, China.
- AI for Science (AI4S)-Preferred Program, Peking University, Shenzhen, China.
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5
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Zhong ZP, Du J, Köstlbacher S, Pjevac P, Orlić S, Sullivan MB. Viral potential to modulate microbial methane metabolism varies by habitat. Nat Commun 2024; 15:1857. [PMID: 38424049 PMCID: PMC10904782 DOI: 10.1038/s41467-024-46109-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Methane is a potent greenhouse gas contributing to global warming. Microorganisms largely drive the biogeochemical cycling of methane, yet little is known about viral contributions to methane metabolism (MM). We analyzed 982 publicly available metagenomes from host-associated and environmental habitats containing microbial MM genes, expanding the known MM auxiliary metabolic genes (AMGs) from three to 24, including seven genes exclusive to MM pathways. These AMGs are recovered on 911 viral contigs predicted to infect 14 prokaryotic phyla including Halobacteriota, Methanobacteriota, and Thermoproteota. Of those 24, most were encoded by viruses from rumen (16/24), with substantially fewer by viruses from environmental habitats (0-7/24). To search for additional MM AMGs from an environmental habitat, we generate metagenomes from methane-rich sediments in Vrana Lake, Croatia. Therein, we find diverse viral communities, with most viruses predicted to infect methanogens and methanotrophs and some encoding 13 AMGs that can modulate host metabolisms. However, none of these AMGs directly participate in MM pathways. Together these findings suggest that the extent to which viruses use AMGs to modulate host metabolic processes (e.g., MM) varies depending on the ecological properties of the habitat in which they dwell and is not always predictable by habitat biogeochemical properties.
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Affiliation(s)
- Zhi-Ping Zhong
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA
| | - Jingjie Du
- Department of Microbiology, Ohio State University, Columbus, OH, USA
- Division of Nutritional Science, Cornell University, Ithaca, NY, USA
| | - Stephan Köstlbacher
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, the Netherlands
| | - Petra Pjevac
- Division of Microbial Ecology, Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, Vienna, Austria
| | - Sandi Orlić
- Division of Materials Chemistry, Ruđer Bošković Institute, Zagreb, Croatia.
- Center of Excellence for Science and Technology-Integration of Mediterranean Region, Zagreb, Croatia.
| | - Matthew B Sullivan
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA.
- Department of Microbiology, Ohio State University, Columbus, OH, USA.
- Center of Microbiome Science, Ohio State University, Columbus, OH, USA.
- Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, USA.
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6
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Chai Z, Liu Y, Jia S, Li F, Hu Z, Deng Y, Yue C, Tang YZ. DNA and RNA Stability of Marine Microalgae in Cold-Stored Sediments and Its Implications in Metabarcoding Analyses. Int J Mol Sci 2024; 25:1724. [PMID: 38339002 PMCID: PMC10855355 DOI: 10.3390/ijms25031724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
The ever-increasing applications of metabarcoding analyses for environmental samples demand a well-designed assessment of the stability of DNA and RNA contained in cells that are deposited or buried in marine sediments. We thus conducted a qPCR quantification of the DNA and RNA in the vegetative cells of three microalgae entrapped in facsimile marine sediments and found that >90% of DNA and up to 99% of RNA for all microalgal species were degraded within 60 days at 4 °C. A further examination of the potential interference of the relic DNA of the vegetative cells with resting cyst detection in sediments was performed via a metabarcoding analysis in artificial marine sediments spiked with the vegetative cells of two Kareniaceae dinoflagellates and the resting cysts of another three dinoflagellates. The results demonstrated a dramatic decrease in the relative abundances of the two Kareniaceae dinoflagellates in 120 days, while those of the three resting cysts increased dramatically. Together, our results suggest that a positive detection of microalgae via metabarcoding analysis in DNA or RNA extracted from marine sediments strongly indicates the presence of intact or viable cysts or spores due to the rapid decay of relic DNA/RNA. This study provides a solid basis for the data interpretation of metabarcoding surveys, particularly in resting cyst detection.
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Affiliation(s)
- Zhaoyang Chai
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (Z.C.); (Y.L.); (F.L.); (Z.H.); (Y.D.); (C.Y.)
- Laoshan Laboratory, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yuyang Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (Z.C.); (Y.L.); (F.L.); (Z.H.); (Y.D.); (C.Y.)
- Laoshan Laboratory, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Siyang Jia
- Yellow Sea and East Sea Buoy Observation Station, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;
| | - Fengting Li
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (Z.C.); (Y.L.); (F.L.); (Z.H.); (Y.D.); (C.Y.)
- Laoshan Laboratory, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhangxi Hu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (Z.C.); (Y.L.); (F.L.); (Z.H.); (Y.D.); (C.Y.)
- Laoshan Laboratory, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yunyan Deng
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (Z.C.); (Y.L.); (F.L.); (Z.H.); (Y.D.); (C.Y.)
- Laoshan Laboratory, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Caixia Yue
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (Z.C.); (Y.L.); (F.L.); (Z.H.); (Y.D.); (C.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying-Zhong Tang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; (Z.C.); (Y.L.); (F.L.); (Z.H.); (Y.D.); (C.Y.)
- Laoshan Laboratory, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
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7
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Jitsuno K, Hoshino T, Nishikawa Y, Kogawa M, Mineta K, Strasser M, Ikehara K, Everest J, Maeda L, Inagaki F, Takeyama H. Comparative single-cell genomics of Atribacterota JS1 in the Japan Trench hadal sedimentary biosphere. mSphere 2024; 9:e0033723. [PMID: 38170974 PMCID: PMC10826368 DOI: 10.1128/msphere.00337-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024] Open
Abstract
Deep-sea and subseafloor sedimentary environments host heterotrophic microbial communities that contribute to Earth's carbon cycling. However, the potential metabolic functions of individual microorganisms and their biogeographical distributions in hadal ocean sediments remain largely unexplored. In this study, we conducted single-cell genome sequencing on sediment samples collected from six sites (7,445-8,023 m water depth) along an approximately 500 km transect of the Japan Trench during the International Ocean Discovery Program Expedition 386. A total of 1,886 single-cell amplified genomes (SAGs) were obtained, offering comprehensive genetic insights into sedimentary microbial communities in surface sediments (<1 m depth) above the sulfate-methane transition zone along the Japan Trench. Our genome data set included 269 SAGs from Atribacterota JS1, the predominant bacterial clade in these hadal environments. Phylogenetic analysis classified SAGs into nine distinct phylotypes, whereas metagenome-assembled genomes were categorized into only two phylotypes, advancing JS1 diversity coverage through a single cell-based approach. Comparative genomic analysis of JS1 lineages from different habitats revealed frequent detection of genes related to organic carbon utilization, such as extracellular enzymes like clostripain and α-amylase, and ABC transporters of oligopeptide from Japan Trench members. Furthermore, specific JS1 phylotypes exhibited a strong correlation with in situ methane concentrations and contained genes involved in glycine betaine metabolism. These findings suggest that the phylogenomically diverse and novel Atribacterota JS1 is widely distributed in Japan Trench sediment, playing crucial roles in carbon cycling within the hadal sedimentary biosphere.IMPORTANCEThe Japan Trench represents tectonically active hadal environments associated with Pacific plate subduction beneath the northeastern Japan arc. This study, for the first time, documented a large-scale single-cell and metagenomic survey along an approximately 500 km transect of the Japan Trench, obtaining high-quality genomic information on hadal sedimentary microbial communities. Single-cell genomics revealed the predominance of diverse JS1 lineages not recoverable through conventional metagenomic binning. Their metabolic potential includes genes related to the degradation of organic matter, which contributes to methanogenesis in the deeper layers. Our findings enhance understanding of sedimentary microbial communities at water depths exceeding 7,000 m and provide new insights into the ecological role of biogeochemical carbon cycling in the hadal sedimentary biosphere.
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Affiliation(s)
- Kana Jitsuno
- Graduate School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
- CBBD-OIL, AIST-Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Tatsuhiko Hoshino
- Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Nankoku, Kochi, Japan
| | - Yohei Nishikawa
- CBBD-OIL, AIST-Waseda University, Shinjuku-ku, Tokyo, Japan
- Research organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Masato Kogawa
- Research organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Katsuhiko Mineta
- CBBD-OIL, AIST-Waseda University, Shinjuku-ku, Tokyo, Japan
- Research organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo, Japan
- Marine Open Innovation Institute, Shizuoka, Japan
| | - Michael Strasser
- Department of Geology, University of Innsbruck, Innsbruck, Austria
| | - Ken Ikehara
- Research Institute of Geology and Geoinformation, AIST Geological Survey of Japan, Tsukuba, Japan
| | | | - Lena Maeda
- Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), JAMSTEC, Yokohama, Japan
| | - Fumio Inagaki
- Research organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo, Japan
- Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), JAMSTEC, Yokohama, Japan
- Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Haruko Takeyama
- Graduate School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
- CBBD-OIL, AIST-Waseda University, Shinjuku-ku, Tokyo, Japan
- Research organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo, Japan
- Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Waseda University, Tokyo, Japan
| | - IODP Expedition 386 ScientistsBellanovaPieroBrunetMorganeCaiZhirongCattaneoAntonioHochmuthKatharinaHsiungKanhsiIshizawaTakashiItakiTakuyaJitsunoKanaJohnsonJoelKanamatsuToshiyaKeepMyraKiokaArataMaerzChristianMcHughCeciliaMicallefAaronMinLuoPandeyDhananjaiProustJean NoelRasburyTroyRiedingerNataschaBaoRuiSatoguchiYasufumiSawyerDerekSeibertChloeSilverMaxwellStraubSusanneVirtasaloJoonasWangYonghongWuTing-WeiZellersSarahKöllingMartinHuangJyh-Jaan StevenNagahashiYoshitaka
- Graduate School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
- CBBD-OIL, AIST-Waseda University, Shinjuku-ku, Tokyo, Japan
- Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Nankoku, Kochi, Japan
- Research organization for Nano and Life Innovation, Waseda University, Shinjuku-ku, Tokyo, Japan
- Marine Open Innovation Institute, Shizuoka, Japan
- Department of Geology, University of Innsbruck, Innsbruck, Austria
- Research Institute of Geology and Geoinformation, AIST Geological Survey of Japan, Tsukuba, Japan
- British Geological Survey, Edinburgh, United Kingdom
- Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), JAMSTEC, Yokohama, Japan
- Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai, Japan
- Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Waseda University, Tokyo, Japan
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8
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Schauberger C, Thamdrup B, Lemonnier C, Trouche B, Poulain J, Wincker P, Arnaud-Haond S, Glud RN, Maignien L. Metagenome-assembled genomes of deep-sea sediments: changes in microbial functional potential lag behind redox transitions. ISME COMMUNICATIONS 2024; 4:ycad005. [PMID: 38282644 PMCID: PMC10809760 DOI: 10.1093/ismeco/ycad005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 01/30/2024]
Abstract
Hadal sediments are hotspots of microbial activity in the deep sea and exhibit strong biogeochemical gradients. But although these gradients are widely assumed to exert selective forces on hadal microbial communities, the actual relationship between biogeochemistry, functional traits, and microbial community structure remains poorly understood. We tested whether the biogeochemical conditions in hadal sediments select for microbes based on their genomic capacity for respiration and carbohydrate utilization via a metagenomic analysis of over 153 samples from the Atacama Trench region (max. depth = 8085 m). The obtained 1357 non-redundant microbial genomes were affiliated with about one-third of all known microbial phyla, with more than half belonging to unknown genera. This indicated that the capability to withstand extreme hydrostatic pressure is a phylogenetically widespread trait and that hadal sediments are inhabited by diverse microbial lineages. Although community composition changed gradually over sediment depth, these changes were not driven by selection for respiratory or carbohydrate degradation capability in the oxic and nitrogenous zones, except in the case of anammox bacteria and nitrifying archaea. However, selection based on respiration and carbohydrate degradation capacity did structure the communities of the ferruginous zone, where aerobic and nitrogen respiring microbes declined exponentially (half-life = 125-419 years) and were replaced by subsurface communities. These results highlight a delayed response of microbial community composition to selective pressure imposed by redox zonation and indicated that gradual changes in microbial composition are shaped by the high-resilience and slow growth of microbes in the seafloor.
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Affiliation(s)
- Clemens Schauberger
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Bo Thamdrup
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Clarisse Lemonnier
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Blandine Trouche
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Julie Poulain
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Sophie Arnaud-Haond
- MARBEC, CNRS, IRD, Institut Français de Recherche pour L'Exploitation de la Mer, Univ Montpellier, 34200 Sète, France
| | - Ronnie N Glud
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Lois Maignien
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
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9
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Qin C, Zhang RH, Li Z, Zhao HM, Li YW, Feng NX, Li H, Cai QY, Hu X, Gao Y, Xiang L, Mo CH, Xing B. Insights into the enzymatic degradation of DNA expedited by typical perfluoroalkyl acids. ECO-ENVIRONMENT & HEALTH (ONLINE) 2023; 2:278-286. [PMID: 38435362 PMCID: PMC10902504 DOI: 10.1016/j.eehl.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/27/2023] [Accepted: 09/05/2023] [Indexed: 03/05/2024]
Abstract
Perfluoroalkyl acids (PFAAs) are considered forever chemicals, gaining increasing attention for their hazardous impacts. However, the ecological effects of PFAAs remain unclear. Environmental DNA (eDNA), as the environmental gene pool, is often collected for evaluating the ecotoxicological effects of pollutants. In this study, we found that all PFAAs investigated, including perfluorohexanoic acid, perfluorooctanoic acid, perfluorononanoic acid, and perfluorooctane sulfonate, even at low concentrations (0.02 and 0.05 mg/L), expedited the enzymatic degradation of DNA in a nonlinear dose-effect relationship, with DNA degradation fragment sizes being lower than 1,000 bp and 200 bp after 15 and 30 min of degradation, respectively. This phenomenon was attributed to the binding interaction between PFAAs and AT bases in DNA via groove binding. van der Waals force (especially dispersion force) and hydrogen bonding are the main binding forces. DNA binding with PFAAs led to decreased base stacking and right-handed helicity, resulting in loose DNA structure exposing more digestion sites for degrading enzymes, and accelerating the enzymatic degradation of DNA. The global ecological risk evaluation results indicated that PFAA contamination could cause medium and high molecular ecological risk in 497 samples from 11 contamination-hot countries (such as the USA, Canada, and China). The findings of this study show new insights into the influence of PFAAs on the environmental fates of biomacromolecules and reveal the hidden molecular ecological effects of PFAAs in the environment.
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Affiliation(s)
- Chao Qin
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Run-Hao Zhang
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Zekai Li
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Hai-Ming Zhao
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Yan-Wen Li
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Nai-Xian Feng
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Hui Li
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Quan-Ying Cai
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Xiaojie Hu
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanzheng Gao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lei Xiang
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Ce-Hui Mo
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States
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10
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Xue Y, Abdullah Al M, Chen H, Xiao P, Zhang H, Jeppesen E, Yang J. Relic DNA obscures DNA-based profiling of multiple microbial taxonomic groups in a river-reservoir ecosystem. Mol Ecol 2023; 32:4940-4952. [PMID: 37452629 DOI: 10.1111/mec.17071] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/08/2023] [Accepted: 07/03/2023] [Indexed: 07/18/2023]
Abstract
Numerous studies have investigated the spatiotemporal variability in water microbial communities, yet the effects of relic DNA on microbial community profiles, especially microeukaryotes, remain far from fully understood. Here, total and active bacterial and microeukaryotic community compositions were characterized using propidium monoazide (PMA) treatment coupled with high-throughput sequencing in a river-reservoir ecosystem. Beta diversity analysis showed a significant difference in community composition between both the PMA untreated and treated bacteria and microeukaryotes; however, the differentiating effect was much stronger for microeukaryotes. Relic DNA only resulted in underestimation of the relative abundances of Bacteroidota and Nitrospirota, while other bacterial taxa exhibited no significant changes. As for microeukaryotes, the relative abundances of some phytoplankton (e.g. Chlorophyta, Dinoflagellata and Ochrophyta) and fungi were greater after relic DNA removal, whereas Cercozoa and Ciliophora showed the opposite trend. Moreover, relic DNA removal weakened the size and complexity of cross-trophic microbial networks and significantly changed the relationships between environmental factors and microeukaryotic community composition. However, there was no significant difference in the rates of temporal community turnover between the PMA untreated and treated samples for either bacteria or microeukaryotes. Overall, our results imply that the presence of relic DNA in waters can give misleading information of the active microbial community composition, co-occurrence networks and their relationships with environmental conditions. More studies of the abundance, decay rate and functioning of nonviable DNA in freshwater ecosystems are highly recommended in the future.
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Affiliation(s)
- Yuanyuan Xue
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Mamun Abdullah Al
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Huihuang Chen
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Peng Xiao
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Hongteng Zhang
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Erik Jeppesen
- Department of Ecoscience, Aarhus University, Aarhus, Denmark
- Sino-Danish Centre for Education and Research, Beijing, China
- Limnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, Ankara, Turkey
- Institute of Marine Sciences, Middle East Technical University, Mersin, Turkey
| | - Jun Yang
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
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11
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Zvi-Kedem T, Vintila S, Kleiner M, Tchernov D, Rubin-Blum M. Metabolic handoffs between multiple symbionts may benefit the deep-sea bathymodioline mussels. ISME COMMUNICATIONS 2023; 3:48. [PMID: 37210404 PMCID: PMC10199937 DOI: 10.1038/s43705-023-00254-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 04/25/2023] [Accepted: 05/11/2023] [Indexed: 05/22/2023]
Abstract
Bathymodioline mussels rely on thiotrophic and/or methanotrophic chemosynthetic symbionts for nutrition, yet, secondary heterotrophic symbionts are often present and play an unknown role in the fitness of the organism. The bathymodioline Idas mussels that thrive in gas seeps and on sunken wood in the Mediterranean Sea and the Atlantic Ocean, host at least six symbiont lineages that often co-occur. These lineages include the primary symbionts chemosynthetic methane- and sulfur-oxidizing gammaproteobacteria, and the secondary symbionts, Methylophagaceae, Nitrincolaceae and Flavobacteriaceae, whose physiology and metabolism are obscure. Little is known about if and how these symbionts interact or exchange metabolites. Here we curated metagenome-assembled genomes of Idas modiolaeformis symbionts and used genome-centered metatranscriptomics and metaproteomics to assess key symbiont functions. The Methylophagaceae symbiont is a methylotrophic autotroph, as it encoded and expressed the ribulose monophosphate and Calvin-Benson-Bassham cycle enzymes, particularly RuBisCO. The Nitrincolaceae ASP10-02a symbiont likely fuels its metabolism with nitrogen-rich macromolecules and may provide the holobiont with vitamin B12. The Urechidicola (Flavobacteriaceae) symbionts likely degrade glycans and may remove NO. Our findings indicate that these flexible associations allow for expanding the range of substrates and environmental niches, via new metabolic functions and handoffs.
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Affiliation(s)
- Tal Zvi-Kedem
- Biology Department, National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa, 3108000, Israel
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Simina Vintila
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Dan Tchernov
- Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Maxim Rubin-Blum
- Biology Department, National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa, 3108000, Israel.
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12
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Dick JM, Tan J. Chemical Links Between Redox Conditions and Estimated Community Proteomes from 16S rRNA and Reference Protein Sequences. MICROBIAL ECOLOGY 2023; 85:1338-1355. [PMID: 35503575 DOI: 10.1007/s00248-022-01988-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/28/2022] [Indexed: 05/10/2023]
Abstract
Environmental influences on community structure are often assessed through multivariate analyses in order to relate microbial abundances to separately measured physicochemical variables. However, genes and proteins are themselves chemical entities; in combination with genome databases, differences in microbial abundances directly encode for chemical variability. We predicted that the carbon oxidation state of estimated community proteomes, obtained by combining taxonomic abundances from published 16S rRNA gene sequencing datasets with reference microbial proteomes from the NCBI Reference Sequence (RefSeq) database, would reflect environmental oxidation-reduction conditions. Analysis of multiple datasets confirms the geobiochemical predictions for environmental redox gradients in hydrothermal systems, stratified lakes and marine environments, and shale gas wells. The geobiochemical signal is largest for the steep redox gradients associated with hydrothermal systems and between injected water and produced fluids from shale gas wells, demonstrating that microbial community composition can be a chemical proxy for environmental redox gradients. Although estimates of oxidation state from 16S amplicon and metagenomic sequences are correlated, the 16S-based estimates show stronger associations with redox gradients in some environments.
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Affiliation(s)
- Jeffrey M Dick
- Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, School of Geosciences and Info-Physics, Central South University, Changsha, 410083, China.
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
| | - Jingqiang Tan
- Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, School of Geosciences and Info-Physics, Central South University, Changsha, 410083, China
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13
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Zhang C, Fang YX, Yin X, Lai H, Kuang Z, Zhang T, Xu XP, Wegener G, Wang JH, Dong X. The majority of microorganisms in gas hydrate-bearing subseafloor sediments ferment macromolecules. MICROBIOME 2023; 11:37. [PMID: 36864529 PMCID: PMC9979476 DOI: 10.1186/s40168-023-01482-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 01/30/2023] [Indexed: 06/01/2023]
Abstract
BACKGROUND Gas hydrate-bearing subseafloor sediments harbor a large number of microorganisms. Within these sediments, organic matter and upward-migrating methane are important carbon and energy sources fueling a light-independent biosphere. However, the type of metabolism that dominates the deep subseafloor of the gas hydrate zone is poorly constrained. Here we studied the microbial communities in gas hydrate-rich sediments up to 49 m below the seafloor recovered by drilling in the South China Sea. We focused on distinct geochemical conditions and performed metagenomic and metatranscriptomic analyses to characterize microbial communities and their role in carbon mineralization. RESULTS Comparative microbial community analysis revealed that samples above and in sulfate-methane interface (SMI) zones were clearly distinguished from those below the SMI. Chloroflexota were most abundant above the SMI, whereas Caldatribacteriota dominated below the SMI. Verrucomicrobiota, Bathyarchaeia, and Hadarchaeota were similarly present in both types of sediment. The genomic inventory and transcriptional activity suggest an important role in the fermentation of macromolecules. In contrast, sulfate reducers and methanogens that catalyze the consumption or production of commonly observed chemical compounds in sediments are rare. Methanotrophs and alkanotrophs that anaerobically grow on alkanes were also identified to be at low abundances. The ANME-1 group actively thrived in or slightly below the current SMI. Members from Heimdallarchaeia were found to encode the potential for anaerobic oxidation of short-chain hydrocarbons. CONCLUSIONS These findings indicate that the fermentation of macromolecules is the predominant energy source for microorganisms in deep subseafloor sediments that are experiencing upward methane fluxes. Video Abstract.
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Affiliation(s)
- Chuwen Zhang
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, China
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Yun-Xin Fang
- Guangzhou Marine Geological Survey, China Geological Survey, Ministry of Natural Resources, Guangzhou, China
| | - Xiuran Yin
- Faculty of Biology/Chemistry, University of Bremen, Bremen, Germany
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Hongfei Lai
- Guangzhou Marine Geological Survey, China Geological Survey, Ministry of Natural Resources, Guangzhou, China
| | - Zenggui Kuang
- Guangzhou Marine Geological Survey, China Geological Survey, Ministry of Natural Resources, Guangzhou, China
| | - Tianxueyu Zhang
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, China
| | - Xiang-Po Xu
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, China
| | - Gunter Wegener
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Jiang-Hai Wang
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai, China.
| | - Xiyang Dong
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China.
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14
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Flemming HC, van Hullebusch ED, Neu TR, Nielsen PH, Seviour T, Stoodley P, Wingender J, Wuertz S. The biofilm matrix: multitasking in a shared space. Nat Rev Microbiol 2023; 21:70-86. [PMID: 36127518 DOI: 10.1038/s41579-022-00791-0] [Citation(s) in RCA: 161] [Impact Index Per Article: 161.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2022] [Indexed: 01/20/2023]
Abstract
The biofilm matrix can be considered to be a shared space for the encased microbial cells, comprising a wide variety of extracellular polymeric substances (EPS), such as polysaccharides, proteins, amyloids, lipids and extracellular DNA (eDNA), as well as membrane vesicles and humic-like microbially derived refractory substances. EPS are dynamic in space and time and their components interact in complex ways, fulfilling various functions: to stabilize the matrix, acquire nutrients, retain and protect eDNA or exoenzymes, or offer sorption sites for ions and hydrophobic substances. The retention of exoenzymes effectively renders the biofilm matrix an external digestion system influencing the global turnover of biopolymers, considering the ubiquitous relevance of biofilms. Physico-chemical and biological interactions and environmental conditions enable biofilm systems to morph into films, microcolonies and macrocolonies, films, ridges, ripples, columns, pellicles, bubbles, mushrooms and suspended aggregates - in response to the very diverse conditions confronting a particular biofilm community. Assembly and dynamics of the matrix are mostly coordinated by secondary messengers, signalling molecules or small RNAs, in both medically relevant and environmental biofilms. Fully deciphering how bacteria provide structure to the matrix, and thus facilitate and benefit from extracellular reactions, remains the challenge for future biofilm research.
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Affiliation(s)
- Hans-Curt Flemming
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
| | | | - Thomas R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Thomas Seviour
- Aarhus University Centre for Water Technology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, USA.,Department of Orthopaedics, The Ohio State University, Columbus, OH, USA
| | - Jost Wingender
- University of Duisburg-Essen, Biofilm Centre, Department of Aquatic Microbiology, Essen, Germany
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
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15
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Conte C, Apostolaki ET, Vizzini S, Migliore L. A Tight Interaction between the Native Seagrass Cymodocea nodosa and the Exotic Halophila stipulacea in the Aegean Sea Highlights Seagrass Holobiont Variations. PLANTS (BASEL, SWITZERLAND) 2023; 12:350. [PMID: 36679063 PMCID: PMC9863530 DOI: 10.3390/plants12020350] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Seagrasses harbour bacterial communities with which they constitute a functional unit called holobiont that responds as a whole to environmental changes. Epiphytic bacterial communities rapidly respond to both biotic and abiotic factors, potentially contributing to the host fitness. The Lessepsian migrant Halophila stipulacea has a high phenotypical plasticity and harbours a highly diverse epiphytic bacterial community, which could support its invasiveness in the Mediterranean Sea. The current study aimed to evaluate the Halophila/Cymodocea competition in the Aegean Sea by analysing each of the two seagrasses in a meadow zone where these intermingled, as well as in their monospecific zones, at two depths. Differences in holobionts were evaluated using seagrass descriptors (morphometric, biochemical, elemental, and isotopic composition) to assess host changes, and 16S rRNA gene to identify bacterial community structure and composition. An Indicator Species Index was used to identify bacteria significantly associated with each host. In mixed meadows, native C. nodosa was shown to be affected by the presence of exotic H. stipulacea, in terms of both plant descriptors and bacterial communities, while H. stipulacea responded only to environmental factors rather than C. nodosa proximity. This study provided evidence of the competitive advantage of H. stipulacea on C. nodosa in the Aegean Sea and suggests the possible use of associated bacterial communities as an ecological seagrass descriptor.
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Affiliation(s)
- Chiara Conte
- PhD Program in Evolutionary Biology and Ecology, University of Rome Tor Vergata, 00133 Rome, Italy
- Laboratory of Ecology and Ecotoxicology, Department of Biology, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Eugenia T. Apostolaki
- Institute of Oceanography, Hellenic Centre for Marine Research, P.O. Box 2214, 71003 Heraklion, Crete, Greece
| | - Salvatrice Vizzini
- Department of Earth and Marine Sciences, University of Palermo, Via Archirafi 18, 90123 Palermo, Italy
- CoNISMa, National Interuniversity Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Roma, Italy
| | - Luciana Migliore
- Laboratory of Ecology and Ecotoxicology, Department of Biology, University of Rome Tor Vergata, 00133 Rome, Italy
- eCampus University, Via Isimbardi 10, 22060 Novedrate (CO), Italy
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16
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Bell E, Rattray JE, Sloan K, Sherry A, Pilloni G, Hubert CRJ. Hyperthermophilic endospores germinate and metabolize organic carbon in sediments heated to 80°C. Environ Microbiol 2022; 24:5534-5545. [PMID: 36100999 PMCID: PMC9826295 DOI: 10.1111/1462-2920.16167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 08/10/2022] [Indexed: 01/11/2023]
Abstract
Cold surface sediments host a seedbank of functionally diverse thermophilic bacteria. These thermophiles are present as endospores, which are widely dispersed in aquatic environments. Here, we investigated the functional potential of endospore populations in cold surface sediments heated to 80°C. Microbial production of acetate was observed at 80°C and could be enhanced by supplying additional organic carbon substrates. Comparison of 16S rRNA gene amplicon libraries from 80°C enrichments to sediments heated to lower temperatures (50-70°C) showed that temperature selects for distinct populations of endospore-forming bacteria. Whereas sulfate-reducing thermophiles were enriched in 50-70°C incubations, 80°C exceeds their thermal tolerance and selects for hyperthermophilic organotrophic bacteria that are similarly detected in amplicon libraries from sediments heated to 90°C. Genome-resolved metagenomics revealed novel carbon cycling members of Symbiobacteriales, Thermosediminibacteraceae, Thermanaeromonas and Calditerricola with the genomic potential for the degradation of carbohydrates, sugars, amino acids and nucleotides. Endospores of thermophilic bacteria are deposited on seabed sediments worldwide where they remain dormant as they are buried in the accumulating sediments. Our results suggest that endospore populations could be activated by temperature increases encountered during burial and show the potential for organotrophic metabolic activity contributing to acetate generation in deep hot sediments.
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Affiliation(s)
- Emma Bell
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada,School of Natural and Environmental SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Jayne E. Rattray
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
| | - Kathryn Sloan
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
| | - Angela Sherry
- Hub for Biotechnology in the Built Environment, Department of Applied SciencesNorthumbria UniversityNewcastle upon TyneUK
| | - Giovanni Pilloni
- ExxonMobil Technology and Engineering CompanyAnnandaleNew JerseyUSA
| | - Casey R. J. Hubert
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada,School of Natural and Environmental SciencesNewcastle UniversityNewcastle upon TyneUK
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17
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Wang C, Wei W, Zhang YT, Ni BJ. Evaluating the role of biochar in mitigating the inhibition of polyethylene nanoplastics on anaerobic granular sludge. WATER RESEARCH 2022; 221:118855. [PMID: 35949070 DOI: 10.1016/j.watres.2022.118855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
The extensive application of anaerobic granular sludge (AGS) to wastewater treatment for methane recovery has drawn considerable attention to the system performances affected by the presence of emerging contaminants in wastewater such as nanoplastics. However, effective strategies on how to mitigate the inhibition caused by nanoplastics remained unavailable. In this study, a novel strategy using biochar to mitigate the inhibition on the AGS performances caused by polyethylene nanoplastics (PE-NPs) was proposed and the corresponding mitigating mechanisms involved were explored. The PE-NPs solely decreased the level of methane recovery of AGS to 71.3 ± 2.7% of control, which was subsequently increased to 85.6 ± 0.8% of control with the presences of both biochar and PE-NPs, although biochar solely showed no obvious effect on methane production. The addition of biochar also elevated the granule size of AGS, along with AGS integrity based on the morphological observation. Moreover, the distributions of live cells and functional microbes related to acidification and methanation increased with biochar addition compared to sole PE-NPs exposure. More extracellular polymeric substance (EPS) was secreted when biochar was involved in AGS systems, with more protein being detected to maintain the granule structure of AGS. Evaluation of adsorption tests indicated that biochar possessed stronger affinity for PE-NPs than AGS, thus capturing the PE-NPs that would originally contact AGS and posing less toxicity to microorganisms.
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Affiliation(s)
- Chen Wang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Wei Wei
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
| | - Yu-Ting Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
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18
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Muthami JM, Fernández-García L, Tomás M, Wood TK. What is the fate of the biofilm matrix? Environ Microbiol 2022; 24:4495-4499. [PMID: 35912827 DOI: 10.1111/1462-2920.16097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 06/04/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Joy M Muthami
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Laura Fernández-García
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA.,Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - María Tomás
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
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19
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Bacterial Necromass Is Rapidly Metabolized by Heterotrophic Bacteria and Supports Multiple Trophic Levels of the Groundwater Microbiome. Microbiol Spectr 2022; 10:e0043722. [PMID: 35699474 PMCID: PMC9431026 DOI: 10.1128/spectrum.00437-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Pristine groundwater is a highly stable environment with microbes adapted to dark, oligotrophic conditions. Input events like heavy rainfalls can introduce the excess particulate organic matter, including surface-derived microorganisms, thereby disturbing the groundwater microbiome. Some surface-derived bacteria will not survive this translocation, leading to an input of necromass to the groundwater. Here, we investigated the effects of necromass addition to the microbial community in fractured bedrock groundwater, using groundwater mesocosms as model systems. We followed the uptake of 13C-labeled necromass by the bacterial and eukaryotic groundwater community quantitatively and over time using a complementary protein-stable and DNA-stable isotope probing approach. Necromass was rapidly depleted in the mesocosms within 4 days, accompanied by a strong decrease in Shannon diversity and a 10-fold increase in bacterial 16S rRNA gene copy numbers. Species of Flavobacterium, Massilia, Rheinheimera, Rhodoferax, and Undibacterium dominated the microbial community within 2 days and were identified as key players in necromass degradation, based on a 13C incorporation of >90% in their peptides. Their proteomes comprised various proteins for uptake and transport functions and amino acid metabolization. After 4 and 8 days, the autotrophic and mixotrophic taxa Nitrosomonas, Limnohabitans, Paucibacter, and Acidovorax increased in abundance with a 13C incorporation between 0.5% and 23%. Likewise, eukaryotes assimilated necromass-derived carbon either directly or indirectly. Our data point toward a fast and exclusive uptake of labeled necromass by a few specialists followed by a concerted action of groundwater microorganisms, including autotrophs presumably fueled by released, reduced nitrogen and sulfur compounds generated during necromass degradation. IMPORTANCE Subsurface microbiomes provide essential ecosystem services, like the generation of drinking water. These ecosystems are devoid of light-driven primary production, and microbial life is adapted to the resulting oligotrophic conditions. Modern groundwater is most vulnerable to anthropogenic and climatic impacts. Heavy rainfalls, which will increase with climate change, can result in high surface inputs into shallow aquifers by percolation or lateral flow. These inputs include terrestrial organic matter and surface-derived microbes that are not all capable to flourish in aquatic subsurface habitats. Here, we investigated the response of groundwater mesocosms to the addition of bacterial necromass, simulating event-driven surface input. We found that the groundwater microbiome responds with a rapid bloom of only a few primary degraders, followed by the activation of typical groundwater autotrophs and mixotrophs, as well as eukaryotes. Our results suggest that this multiphase strategy is essential to maintain the balance of the groundwater microbiome to provide ecosystem services.
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20
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Brasell KA, Pochon X, Howarth J, Pearman JK, Zaiko A, Thompson L, Vandergoes MJ, Simon KS, Wood SA. Shifts in DNA yield and biological community composition in stored sediment: implications for paleogenomic studies. METABARCODING AND METAGENOMICS 2022. [DOI: 10.3897/mbmg.6.78128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Lake sediments hold a wealth of information from past environments that is highly valuable for paleolimnological reconstructions. These studies increasingly apply modern molecular tools targeting sedimentary DNA (sedDNA). However, sediment core sampling can be logistically difficult, making immediate subsampling for sedDNA challenging. Sediment cores are often refrigerated (4 °C) for weeks or months before subsampling. We investigated the impact of storage time on changes in DNA (purified or as cell lysate) concentrations and shifts in biological communities following storage of lake surface sediment at 4 °C for up to 24 weeks. Sediment samples (~ 0.22 g, in triplicate per time point) were spiked with purified DNA (100 or 200 ng) or lysate from a brackish water cyanobacterium that produces the cyanotoxin nodularin or non-spiked. Samples were analysed every 1–4 weeks over a 24-week period. Droplet digital PCR showed no significant decrease in the target gene (nodularin synthetase – subunit F; ndaF) over the 24-week period for samples spiked with purified DNA, while copy number decreased by more than half in cell lysate-spiked samples. There was significant change over time in bacteria and eukaryotic community composition assessed using metabarcoding. Amongst bacteria, the cyanobacterial signal became negligible after 5 weeks while Proteobacteria increased. In the eukaryotic community, Cercozoa became dominant after 6 weeks. These data demonstrate that DNA yields and community composition data shift significantly when sediments are stored chilled for more than 5 weeks. This highlights the need for rapid subsampling and appropriate storage of sediment core samples for paleogenomic studies.
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21
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Extracellular DNA in environmental samples: Occurrence, extraction, quantification, and impact on microbial biodiversity assessment. Appl Environ Microbiol 2021; 88:e0184521. [PMID: 34818108 DOI: 10.1128/aem.01845-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Environmental DNA, i.e., DNA directly extracted from environmental samples, has been applied to understand microbial communities in the environments and to monitor contemporary biodiversity in the conservation context. Environmental DNA often contains both intracellular DNA (iDNA) and extracellular DNA (eDNA). eDNA can persist in the environment and complicate environmental DNA sequencing-based analyses of microbial communities and biodiversity. Although several studies acknowledged the impact of eDNA on DNA-based profiling of environmental communities, eDNA is still being neglected or ignored in most studies dealing with environmental samples. In this article, we summarize key findings on eDNA in environmental samples and discuss the methods used to extract and quantify eDNA as well as the importance of eDNA on the interpretation of experimental results. We then suggest several factors to consider when designing experiments and analyzing data to negate or determine the contribution of eDNA to environmental DNA-based community analyses. This field of research will be driven forward by: (i) carefully designing environmental DNA extraction pipelines by taking into consideration technical details in methods for eDNA extraction/removal and membrane-based filtration and concentration; (ii) quantifying eDNA in extracted environmental DNA using multiple methods including qPCR and fluorescent DNA binding dyes; (iii) carefully interpretating effect of eDNA on DNA-based community analyses at different taxonomic levels; and (iv) when possible, removing eDNA from environmental samples for DNA-based community analyses.
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